Trowel-grinding machine.



N0. 643,9l4. Patented Feb. 20, I900. E. F. SHAW.

TRUWEL GRINDING MACHINE.

(Application filed June 20, 1896.] (No Model.) 3 Sheets-Sheet l.

Inventor:

THE- NORRIS PETERS 00.. PHoTo-L|'n-1o..wAsH|uu'r0N. n. c.

No. 643.9!4. Patent ed Feb. 20, I900. E. F. SHAW.

TBOWEL GRINDING MACHINE.

(Application filed June 20, 1896.)

3 Sheets-Sheet 2 (No Model.)

FIG. ,3.

Inventor: Edwin J? 15' MM 5y 701:5 fldtorizeya' M a M IIBILIIIIIIIIIIILW Zines-sea.

THi cams PETEKS ca. Paomurno. WASHINGTON, n. c.

No. 643,914. 'Patented Feb. 20, I900.

E. F. SHAW.

TBOWEL GRINDING MACHINE.

(Application filed June 20, 1896.) (No Model.)

3 Sheets5heet 3.

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UNITED STATES PATENT OFFICE.

EDWIN F. SHAW, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE HENRYDISSTON & SONS, INCORPORATED, OF SAME PLACE.

TROWEL-GRINDING MACHINE.

SPECIFICATION forming part of Letters Patent No. 643,914, dated February20, 1900.

Application filed June 20, 1896. Serial No. 596,327. (No model.)

To all whom, it may concern:

Be it known that I, EDWIN F. SHAW, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certainImprovements in Trowel-Grinding Machines,

of which the following is a specification.

The object of my invention is to so construct a machine for grindingtrowels that several trowels can be ground at one operation and in whichthe proper taper will be given to each individual trowel.

In the accompanying drawings, Figure 1 is a plan view of my improvedtrowel-grinding machine. Fig. 2 is an end view. Fig. 3 is a longitudinalsectional view. Fig. 4 is a perspective view of one of the blocks onwhich the trowel-blank is clamped; and Fig. 5 is a View of a trowel,showing the manner in which it is ground on my improved machine.

A is a bed similar to that of an ordinary planing-machine,havin gV-shaped grooves in its upper surface, in which slide the V-shapedribs 1) on the bottom of the table B. This table can be either movedacross the bed by hand or by mechanism similar to that used onplaning-machines. Secured to the bed is a frame D. The uprights d d ofthis frame are in the form of ways, on which are two carriers D, eachhaving a bearing d for the shaft E, on which is mounted thegrinding-wheel E. This shaft is driven in the present instance bybelting which passes over the beltwheel 6, and the shaft, with itsgrindingwheel, is moved longitudinallyin its bearing by means of thehand-lever E rangement the grinding-wheel can be moved laterally overthe face of the table. The carriers D are adjustable vertically by meansof a shaft F, which is provided with a handle f, and this shaft isgeared to screw-shafts F F, which enter the screw-threaded openings inthe carriers, so that on turning the shaft F the carriers will be raisedor lowered, so as to adjust the grinding-wheel toward or from the table.

011 the table B are a series of blocks I of the form clearly shown inthe perspective View, Fig. 4. Each block I is beveled in twodirections-that is, from corner m to the corner w and from 00 to w sothat when the trowel is placed in position on the block, as

By this ar- 1 shown in Fig. 1, it will be ground in such a manner as tobe thicker at the center than at the edges and thicker at the shouldersthan at the point. Each trowel-blank is held to its block by means of aclamp i, which is held to the block by means of the bolt 1', havingahead which is within the undercut slot 7? in the block. The trowel isheld from swinging by stops 2' on each side of the clamp. These stopsare held in the same manner as the clamp, so that when the trowel is inposition it will be rigidly held, so that the wheel can properly grindthe face. Other styles of clamps may be used without departing from myinvention. Under each block is a sheet of rubber J, and the blocks areloosely attached to the table by means of screws j, so that thetrowel-blank will be kept in contact with the grinding-wheel, the rubberacting as a cushion.

The operation of the machine is as follows: The blocks are mounted onthe table and secured thereto with the rubber under-them and the blanksto be ground are adjusted on the blocks. The machine is then set inmotion, so that the table will reciprocate under the grinding-wheel, andas the table reciprocates the grinding-wheel is moved laterally over thetable by operating its lever, so that the surface of the trowel-blankswill be gradually ground to give the proper bevel, so that the thickpart will be at the shank and will gradually bevel oif in bothdirections toward the point.

The machine, as shown, grinds the left hand side of one set oftrowel-blanks and grinds the right-hand side of another set. When thegrinding is completed, the trowelblanks are shifted, so that theopposite sides of the trowels can be ground, thus insuring the propergrinding of the trowels.

By my invention a number of trowels can be ground in one operation, andthe proper taper can be given to the trowel by shaping the blank to thebevel required.

It will be understood that in some instances the blocks I may form partof the table B, although I prefer to make them independent of the table.

I claim as my invention- 1. The combination of a frame, a table machine,of the frame, a bed, means for reciprocating said bed, two rows ofindependent blocks secured to said bed, the surface of each block beingtapered in two directions, clamps on each block extending over onesurface of a trowel-blank so as to secure the said blank in the adjustedposition, the frame having standards, adjustable bearings on thestandards, a driven shaft, a grinding-wheel mounted on said shaft andmeans for moving the shaft longitudinally in its bearings whereby aportion of each trowel-blank can be ground, substantially as described.

3. The combination of a reciprocated table, blocks thereon having asingle beveled face adapted to receive the trowel-blanks, cush' ionsinterposed between the blocks and the table and a grinding-wheel mountedabove the table, substantially as described.

4. The combination in a trowel-grinding machine, of the frame, areciprocated table, a series of blocks secured thereto the surface ofeach block being tapered in two directions, a T-headed groove in eachblock, a clamp, a bolt securing the clamp to the block the head of saidbolt being within the groove, stops against which the trowel-blankrests, with a grinding-wheel for grinding the surface of the blank,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EDWIN I SHAW.

\Vitnesses:

WILL. A. BARR, Jos. H. KLEIN.

